. >> and for the first time today, president obama referred to the attacks that killed three and wounded 176 others as an act of terrorism. he went on to say that the american people refused to be terrorized. tom sherwood has more on the stepped up security here in washington. >>> we begin with tony tull who is live in boston close to where it happened. he tells us the tragedy also brought the city together. tony? >> reporter: and, good afternoon, the details are emerging still, we had an update earlier this morning, we'll hear from the fbi in an hour. one thing i noticed today, throughout the day the folks coming to the scene of the crime and just coming together. people who didn't know each other, people from other states and countries coming together and comforting each other. i just want to show you a sense of the scene, you can see a block away from boylston street, you can't see exactly where the bomb went off, but you can see here the folks who were supposed to celebrate, it has become a time where they will never forget. and you mentioned it, it is a time for them coming together